Sherman M B, Chiu W
W. M. Keck Centre for Computational Biology, Verna and Marrs McLean Department of Biochemistry, Baylor College of Medicine, Houston, TX 77030, USA.
J Microsc. 1997 Dec;188(Pt 3):285-9. doi: 10.1046/j.1365-2818.1997.2450803.x.
Glucose-embedded purple membranes were used as a test specimen to evaluate the reliability of phases retrieved from 400-kV spot-scan images acquired on a 1024 x 1024 slow-scan CCD camera. This specimen was chosen because it represents a broad class of low-contrast radiation-sensitive biological objects and its structure is well established. The amplitudes of computed reflections from these images were strongly damped by the modulation transfer function of the camera. Nevertheless, their phases on average were < 12 degrees different from the reference data of Henderson et al. (1986), Ultramicroscopy, 19, 147-178, up to 8.8 A resolution, which corresponds to 0.8 of the Nyquist frequency of the camera.
嵌入葡萄糖的紫膜被用作测试样本，以评估从在1024×1024慢扫描电荷耦合器件（CCD）相机上获取的400 kV点扫描图像中恢复的相位的可靠性。选择这个样本是因为它代表了一大类低对比度的辐射敏感生物物体，并且其结构已被充分确定。这些图像计算出的反射振幅被相机的调制传递函数强烈衰减。然而，在高达8.8 Å分辨率（对应于相机奈奎斯特频率的0.8）下，它们的相位平均与亨德森等人（1986年，《超微结构》，19卷，147 - 178页）的参考数据相差<12度。
